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Nuclear Notes — Thursday, Dec. 22, 2022

Matthew Wald

I'll be taking a break next week for the holidays, but Nuclear Notes will return on Thursday, January 5, 2023.

The December Holiday Case for Advanced Nuclear

During the darkest days of December, many Americans light up their homes with menorahs, Christmas trees, and perhaps lawn decorations, too. It is good for the soul, but what about the planet?

Christmas trees are mostly lit with LEDs these days, for economy and safety. (All the watts in a light eventually turn into heat, so lower wattage means less chance of ignition.) LED mini-lights are less than one watt per bulb, and an indoor tree might get by on 23 watts. If it burns for 12 hours a day, for 15 days, that comes to 4,000 watt-hours. Any trees strung with incandescent lights, which are barely sold at retail any longer, would use nearly ten times as much.

For the United States, the average carbon footprint of a kilowatt-hour is about .82 pounds. So, all told, the indoor tree would have a carbon footprint of about 3.3 pounds. (Omitting, of course, that once the tree is dead, the carbon that it sequestered in its wood will likely find its way into the atmosphere.) The National Christmas Tree Association predicts sales of 25 to 30 million trees, but this does not count artificial trees that have lights, or the live trees in peoples’ front yards that are draped with lights. Nor does it include plastic Santas and Rudolphs with illuminated noses. Forbes estimated two years ago that holiday lights consume about 35 billion kilowatt-hours, but precision is impossible.

As for Menorahs, estimates vary, but a Hanukkah candle (which is bigger than a candle for a birthday cake, but a lot smaller than a candle in a typical candelabra) emits about 7 grams of carbon dioxide, over however long it takes to burn, and the box that lasts eight days has 44 candles. There’s one candle that’s used to light the others, plus one on the first night, two on the second, three on the third, etc., until you reach 8. That’s 308 grams, about .68 pounds. Across the country, millions are burned.

College dorms, nursing homes, and apartment house lobbies typically use electric menorahs. The one in my lobby, for example, uses 3-watt incandescents, and they burn around the clock. Two burn for eight days, three for seven days, four for six days, and so on, giving a total of about 3,200 watt-hours. That puts the incandescent menorah at about 2.6 pounds of carbon dioxide. An LED model would cut the load to about 400 watt-hours, with .33 pounds of carbon dioxide.

Counting the menorahs that show up in drugstore gift displays next to the 3-foot-tall Christmas elves imported from China, the number is probably in the low millions.

Individually, these numbers are quite small. Even a lit Christmas tree has a smaller footprint than driving a gasoline car five miles. But the impact is not zero, and there are easy ways to make it smaller by cleaning up our electricity mix.

For example, using the biggest footprint here, the one for the Christmas tree that is lit twelve hours a day for fifteen days, we can calculate the carbon dioxide impact of electricity from various sources, using numbers from UN Intergovernmental Panel on Climate Change. The figures used here are for the median estimates gathered in the IPCC study.

If the electric grid relies on coal, the carbon dioxide footprint of that tree is 7.2 pounds. For combined cycle natural gas, it's 4.3 pounds. Getting into renewables, hydropower could shrink the footprint to 2.1 pounds; solar photovoltaic (not counting losses from batteries, which are required for after-dark uses) to .42 pounds; and onshore wind to .10 grams. Nuclear, the only source that could be scaled up enough to realistically meet the country’s festive electric needs clocks in at .11 pounds.

If the Forbes estimate of 35 billion kilowatt-hours is roughly correct, that electricity coming from coal would account for about 29 billion pounds. From nuclear, less than a billion pounds.

Fixing pollution from holiday lights won’t make a lot of difference to the climate, but the numbers do illustrate how the benefits of cleaner electricity sources like nuclear add up.

Two Nuclear Beauties in Madison

Miss America 2023 is a nuclear engineering student at the University of Wisconsin, Grace Stanke.

In an article on the engineering department’s website, Ms. Stanke said she wants to “help change the public perception of nuclear energy and increase awareness of the many benefits of nuclear technology.”

She is a former intern at Constellation, the Exelon subsidiary that operates several reactors in the mid-Atlantic region. She is the 95th Miss America, and the first nuclear engineer to win the title.

And if you visit the campus where she studies, in Madison, be sure to see the University’s 1 Megawatt (thermal) research reactor, an open-pool Triga. It could probably win some kind of beauty contest, too.

Dig Deeper >>>

Reactors Can Make More than Just Electricity, Dow Says Again

Dow Chemical will work with the Idaho National Laboratory to study how a small modular reactor could provide electricity and process heat for a chemical plant on the U.S. Gulf Coast.

Dow got an award under the Energy Department’s GAIN program, for Gateway for Accelerated Innovation in Nuclear. These awards resemble gift certificates, that can be spent on access to government research facilities.

For Dow, this is a longstanding goal. The company contracted in the 1970s to buy steam from a twin-unit nuclear plant under construction across the Tittabawassee River from Dow’s chemical plant in Midland, Mich. But the nuclear plant was canceled because of engineering problems.

At the time, the goal was to save money, but using a reactor for process heat now would cut Dow’s carbon footprint. The company has pledged to be carbon neutral by 2060.

Dig Deeper >>>

The Product is Still Years Away, but the Board is Shaping Up

Radiant Nuclear, a young start-up company in El Segundo, California, is developing a nuclear reactor that is transportable by truck or plane, in a standard shipping container. It was founded by former engineers at SpaceX, who had been working on a reactor for use on the Moon or Mars. The reactor is designed to run on TRISO fuel, also known as “pebbles,” for up to five years, and returned to Radiant for refueling.

The company has announced two additions to its Board of Directors: Stephen G. Burns, who was chairman of the Nuclear Regulatory Commission from January 2015 to January 2017, and was the agency’s General Counsel for years before that. It also added Rachel Slaybaugh, a nuclear engineer who was formerly involved with helping start-ups launch, at Lawrence Berkeley Laboratory and at ARPA-E, the Energy Department’s version of the Advanced Research Projects Agency.

Dig Deeper >>>

The United States has a Strategic Petroleum reserve and a heating oil reserve, and in 2020, Congress allocated $75 million for a uranium reserve, to be filled with material mined within the United States. Now, two companies have signed contracts to sell “yellowcake,” a uranium oxide mixture that is an early stage in the process of making reactor fuel.

Energy Fuels Inc., which will be selling uranium that is already stockpiled in Metropolis, III, a site where yellowcake is converted into a different chemical form, in preparation for enrichment.

Peninsula Energy Limited, a subsidiary of Strata Energy, will also be selling yellowcake that it has previously produced.

Peninsula has also announced that it will re-start uranium production at a site in Wyoming that had been shut since 2019. One of the goals of the reserve is to stimulate domestic production, which had fallen to near zero because of cheap imports from Russia and Kazakhstan, a former Soviet republic.

The effect is like planting wheat to alleviate a shortage of bread. The yellowcake purchases will not help with the more pressing problem, the availability of uranium fuel for advanced reactors. That fuel will have a higher proportion of one type of uranium, uranium-235, than is found in nature, and higher than what is used in today’s reactors. To make it, yellowcake will be converted at Metropolis or elsewhere into uranium hexafluoride, a chemical form that can be heated and turned into a gas, and then fed into centrifuges that will sort the uranium into two different forms.

The Energy Department is also pursuing a program for higher-enrichment uranium fuel, but not fast enough to meet the schedules of the advanced reactor developers.

Dig Deeper >>>

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